Sunbeam, yes it goes on pretty much like the bearing buddy. Very tight fit if it's done right and it takes some prying to get it back off. My problem with grease has always been getting too much in there, and then it squeezing out behind the seal and getting on to the brake shoes. (Electric brakes.) Also, no way of knowing the grease condition without pulling the grease cap. The Oil bath is always viewable with the clear plastic caps. I've only had oil leak out once behind the inner seal, and that was my own fault for bending it a bit when installing it. As long as the seal is set and all else installed correctly, you should never have to add oil. I do pull the hubs and change the oil every few years, mostly so I can check on the brake shoes. As I mentioned earlier, the only concern I have is if one of the caps or cylinders got knocked off. IN that situation, if you didn't catch it right away, you're probably going to fry a bearing and that could create some problems with the spindle too. However, I've also seen smoking grease hubs that were not maintained... For now I'm very happy with the oil bath, and will continue to run them. Colby